1. Field of the Invention
This invention relates to a rebuilt portion of a coke oven heating chamber and more particularly to a method of rebuilding a damaged portion of a coke oven heating chamber by removing deteriorated refractory brick and replacing it by the spraying of refractory material in surrounding relation with thermally destructable forms constructed to form the passageways that convey the flue gas through the heating chamber.
2. Description of the Prior Art
Coke oven batteries include a number of horizontal coke ovens that range up to twenty feet in height and up to fifty feet in length. An oven is approximately eighteen inches wide. Individual ovens are laterally arranged in groups to form a battery. A coke oven has a chamber with opposite open ends closed by doors. Positioned on both sides of a coke oven chamber are heating walls.
Internally of the heating walls are vertical heating flues in which combustion of air and gas takes place and the combustion products are exhausted through the heating flues vertically to a horizontal flue. The products of combustion pass along the horizontal flue and are drawn downwardly through additional heating flues on the other half of the coke oven. Heat is then supplied to the coking chambers from the adjacent heating flues through the heating walls.
The heating walls are heated to an elevated temperature to carry out the coking process. However, the heating walls adjacent the coke oven doors are cooled each time the doors are opened to push the coke from an oven chamber. Consequently, portions of the heating walls are subjected to thermal shock resulting in contraction and expansion of the refractory brick forming the heating walls, particularly the brick adjacent the coke oven doors.
The coke oven doors at both the pushing side and coking side are closed when coal is being coked within the coke oven chambers. These doors are removed when the coke is to be pushed out of the ovens. It is at this time when the refractory brick adjacent the doors are subjected to the maximum thermal shock by cooling of the brick. This causes expansion and contraction of the bricks results in spalling, deterioration, and eventually disintegration of entire brick sections of the heating walls.
U.S. Pat. No. 2,476,305, discloses repair of disintegrated coke oven walls by replacing the old refractory brick with new refractory brick. When the oven walls are to be repaired, heating of the flues at each side of an oven is discontinued and a bulkhead is placed within the oven back of the section to be repaired to shield the workmen from the heat of the walls. The new bricks are laid in courses and tied into the original brick. Such a process is laborious, expensive, and time consuming.
Is is also well known in the iron and steel industry to repair not only cracks in the refractory walls of a coke oven but the refractory walls or lining of a steel making furnace. The cracks are sealed and the refractory surface is relined by a gunning application of a refractory material. The refractory material is formed by mixing a dry mix of refractory binder and aggregate propelled through a hose by a stream of compressed air to a nozzle where a wetting agent, such as water, is supplied for mixture with the dry refractory to form a refractory product in a slurry. The refractory product in slurry form is operable to be sprayed on the interior surface of the coke oven walls for an oven removed from service. It is also known to seal leaks around a closed coke oven door by spraying while the coke oven remains in operation, as illustrated in U.S. Pat. No. 4,189,457.
Similarly it is known to reline the interior surface of a furnace by disposing a spray pipe and nozzle within the furnace. The spray nozzle is directed to spray refractory material into the abraded, eroded, and spalled areas of the refractory lining within the furnace. U.S. Pat. No. 4,127,626 discloses a known apparatus for repairing the lining of a furnace.
U.S. Pat. No. 4,143,104 discloses a method for repairing cracked coke oven walls wherein a gunning composition is applied to a damaged wall portion while the wall portion is at an elevated temperature. After the coke oven chamber is emptied, cracks in the surface of the interior walls are sealed by applying a gunning composition while the wall surfaces are at an elevated temperature. This procedure, however, is not applicable to repair of the heating chamber including heating flues within the walls separating adjacent oven chambers. Due to the thermal shock to which the brickwork of the heating flues are exposed at the ends of a coke oven, the heating flues are destroyed. Because the heating flues are within the heating chamber, repair by external spraying only is successful for internal repair thereby requiring dismantling of the old brick and installation of new brick.
U.S. Pat. No. 4,077,848 discloses apparatus for patching the interior walls and roof of a coke chamber oven by a gunning apparatus mounted on the pusher machine used in removing a charge of coke from the coke oven. By mounting the gunning apparatus directly on the pusher machine, the patching of the cracks is accomplished subsequent to the pushing of the coke from the oven. The patching or sealing composition is sprayed from nozzles located on the head of the pusher ram while the ram moves through the empty coke oven chamber. With this arrangement it is not necessary to permit the coke oven to cool to the extent that workmen may approach closely enough to work on the cracked areas.
It is also well known in the art of repairing the walls of a coke oven to repair leaks in the gas gun and other tubular refractory passages of the coke oven while the refractory brick is still hot and without withdrawing the coke oven from service. U.S. Pat. No. 2,851,760 discloses the penetration of refractory patching material in crevices of the gas gun to restore the refractory material forming the gas gun to seal the gun from gas leaks. The section of the gas gun to be repaired is first dammed off or plugged with a friable plastic material. The plastic dam is expanded into engagement with the hot walls of the gas gun. Thereafter a slurry of leak sealing material is introduced under pressure into the gun and forced into the cracks and crevices to be sealed. The openings from the gas gun to the fuel nozzles are also plugged. One of the members comprising the dam or plug for locating the application of the refractory within the gas gun is an abutment made of wood. During the repair operation, the wood abutment is burned out. After the refractory material has hardened in the cracks, the friable plastic dam and any other foreign solid material which may include the charred wood abutment or portions of the charred wood abutment are removed. Finally the gun opening is reamed or abraded to the desired size to remove excess refractory formed on the inside of the gas gun.
While it has been suggested to repair the damaged interior walls of a coke oven chamber by spraying of refractory material into the cracks in the brickwork and also to gun apply sealing material in crevices of refractory brick around the perimeter of a coke oven door, spray repairing is not suitable for repairing deteriorated bricks forming the interior heating flues within the heating chambers between the coke oven chambers. The present day practice of repairing the damaged heating walls adjacent the coke oven doors by replacing old brick with new brick is laborious and expensive. Therefore, there is need to provide a method of rebuilding the heating walls of a coke oven that does not require the laborious operation of replacing damaged brick with new brick.